some Meltrope questions

[SteveM]

So I'm not allowed to buy any more machines, and it's probably a good thing I have wifey keeping me in check ... otherwise I'd be a mess. BUT I still enjoy tinkering and still don't go out much, yet, so what is there to do? Buy overpriced sound boxes in questionable condition!

I bought the "good condition" Meltrope II from the seller in Oregon which had been listed for YEARS, and the seller explicitly told me long ago that it doesn't sound as good as a 5b. BUT he listed an "excellent condition" Meltrope II with a box, so I bought that, AND the other "good condition" one, too, while I was at it. We worked out a half-decent deal, I guess. Anyway, they both sound, to my ears, pretty great (I'll post a video soon, hopefully). I've had them both apart, cleaned, and reassembled. The "good condition" one has some patched holes in the diaphragm. Still though, they both punch very nicely, and I'm really thrilled.

As you can see from the listing photo, the "good condition" one had a faceplate with some liberally applied black paint, and then really sloppy gold paint over the engravings.

I removed the paint, on both sides, down to the brass, while preserving most of the fine original gold-painted engraving (it looks much better in person).

I don't know what was going on with that black paint, but there didn't seem to be much of any original paint beneath it. My intention was to dunk the faceplate in "brass black" and then clear coat. I think that would very closely match the original grey-black look. I think the bare brass looks rather nice, though, and it gets a little darker every day. Hmmm.

Questions: should the spring screws be reasonably tight, i.e., will their tightness have an effect on the sound? The ball bearings are extremely dirty. Should they be covered in fresh oil or grease? Also, are there parts available from anyone? I've bought rubber backs from the seller on eBay, but I also would entertain a new diaphragm, and I'm also missing a brass washer for the back rubber (this seems very important to have ... I've swapped one out from a Meltrope III in the meantime).

I love the quality of these Meltrope II's and the power they have is really incredible, compared with my 5b's and Victor Ortho. I don't quite know how the extra grunt is possible (I think I've seen it attributed to the gaskets?) but it makes a real difference in my listening. Bamboo (which I'm using exclusively now) really fills the room. My tinkering itch has definitely been scratched!

[Steve]

The original face-plate has a kind of bluish grey "gun metal" finish, not flat painted look. It was plated originally.

[Orchorsol]

They're such great workhorses with such fine sound that I care much less about the appearance than the function, although they are handsome. Yours looks great Steve, even if not the original finish!

Questions: should the spring screws be reasonably tight, i.e., will their tightness have an effect on the sound? The ball bearings are extremely dirty. Should they be covered in fresh oil or grease?

I tend to experiment with screw tightness, though it's hard to say whether I've really heard much difference. I do always clean the ball bearings and put them back with dots of grease. Some people have tried thin rubber or leather pads in with the balls (I believe this was one of Wild's tuning modifications back in the day). Of course, there's also different types of rubber tubing for the gaskets - I always use beige natural rubber (vintage bicycle valve tubing).

Also, are there parts available from anyone? I've bought rubber backs from the seller on eBay, but I also would entertain a new diaphragm, and I'm also missing a brass washer for the back rubber (this seems very important to have ... I've swapped one out from a Meltrope III in the meantime).

Not as far as I know. Soundgen (here on the TMF and eBay) sells sets of 4 ball bearings for the Meltrope III, 2 each of 2 different sizes, but I don't know offhand whether either is the same as those in the Meltrope I & II.
No diaphragms are available to my knowledge and in any case, it's virtually impossible to disassemble them - leave the needle bar fixing well alone!
Some of my Meltrope & EMG soundboxes have no rear washer and I don't think that really makes any difference.
For the back rubbers, I think the ones on eBay are fine, but Chunny (gramophone museum website) sells natural rubber ones which are probably the closest to the originals. I received a super-soft rubber one from someone who makes rubber damping parts for electrical pickups, and it was amazing - increase in bass - but it's so soft that sonic vibrations cause it to gradually move across and fall off the tonearm on a loud record!

[SteveM]

The original face-plate has a kind of bluish grey "gun metal" finish, not flat painted look. It was plated originally.

"Brass Black" does exactly that ... a gun metal finish that sort of works like a dye. Doesn't really shine, though. I'm not sure what to do, might leave the raw brass for awhile.

[SteveM]

They're such great workhorses with such fine sound that I care much less about the appearance than the function, although they are handsome. Yours looks great Steve, even if not the original finish!

Questions: should the spring screws be reasonably tight, i.e., will their tightness have an effect on the sound? The ball bearings are extremely dirty. Should they be covered in fresh oil or grease?

I tend to experiment with screw tightness, though it's hard to say whether I've really heard much difference. I do always clean the ball bearings and put them back with dots of grease. Some people have tried thin rubber or leather pads in with the balls (I believe this was one of Wild's tuning modifications back in the day). Of course, there's also different types of rubber tubing for the gaskets - I always use beige natural rubber (vintage bicycle valve tubing).

Also, are there parts available from anyone? I've bought rubber backs from the seller on eBay, but I also would entertain a new diaphragm, and I'm also missing a brass washer for the back rubber (this seems very important to have ... I've swapped one out from a Meltrope III in the meantime).

Not as far as I know. Soundgen (here on the TMF and eBay) sells sets of 4 ball bearings for the Meltrope III, 2 each of 2 different sizes, but I don't know offhand whether either is the same as those in the Meltrope I & II.
No diaphragms are available to my knowledge and in any case, it's virtually impossible to disassemble them - leave the needle bar fixing well alone!
Some of my Meltrope & EMG soundboxes have no rear washer and I don't think that really makes any difference.
For the back rubbers, I think the ones on eBay are fine, but Chunny (gramophone museum website) sells natural rubber ones which are probably the closest to the originals. I received a super-soft rubber one from someone who makes rubber damping parts for electrical pickups, and it was amazing - increase in bass - but it's so soft that sonic vibrations cause it to gradually move across and fall off the tonearm on a loud record!

Thanks for all of this great info! I'm fine leaving the diaphragm alone, it looks like someone worked quite hard to mend it, and sounding quite nice! And I've been wondering how to get those Chunny rubbers, thanks! My Meltropes seem to be well set, but I want to try some on my 5b's.

[Inigo]

Just pm chunny he's in the forum. The rubbers fit in the back metal neck of both hmv no4 and no5a/b soundboxes directly, snugly. You have to remove the original black rubber neck (with its brass ring adhered inside) and its two screws, and directly install the red rubber collar. Don't install the screws, leave them apart.
The rubber collars have the same outer diameter, but are made with different internal diameters for the different tonearms. Just state the type of tonearm when you ask for the rubber collar.
The advantages are great, supple elastic rubber, etc. Besides that, as you install it with no fixing screws, nor the locking pin, nor the inner brass ring. This allows a snug fitting on the tonearm, very elastic and leak tight.
The absence of the locking pin allows to adjust the needle angle at will, so you can benefit from that to adjust the tracking angle with the grooves, playing with the needle angle and its projection length....

[epigramophone]

Great care must be taken when removing the original HMV rubber isolator. The backs of late No.4 and all No.5a/5b soundboxes are pot metal and easily broken, so much so that UK dealer John Sleep www.windupgram.co.uk has had replica backs manufactured in modern light alloy.

[Steve]

Great care must be taken when removing the original HMV rubber isolator. The backs of late No.4 and all No.5a/5b soundboxes are pot metal and easily broken, so much so that UK dealer John Sleep www.windupgram.co.uk has had replica backs manufactured in modern light alloy.

But these are not identical to the originals and in my opinion miss the whole point of the original design entirely with their mistakenly manufactured solid collar backs which do not have any space inside for the rubber isolators at all, meaning there is a full mechanical fix and continuous contact between the tonearm and soundbox. A complete failure to understand the purpose of isolating the motor vibrations from the soundbox and unwanted resonances from colouring the sound waves emitting from the diaphragm.

[epigramophone]

Great care must be taken when removing the original HMV rubber isolator. The backs of late No.4 and all No.5a/5b soundboxes are pot metal and easily broken, so much so that UK dealer John Sleep www.windupgram.co.uk has had replica backs manufactured in modern light alloy.

But these are not identical to the originals and in my opinion miss the whole point of the original design entirely with their mistakenly manufactured solid collar backs which do not have any space inside for the rubber isolators at all, meaning there is a full mechanical fix and continuous contact between the tonearm and soundbox. A complete failure to understand the purpose of isolating the motor vibrations from the soundbox and unwanted resonances from colouring the sound waves emitting from the diaphragm.

It goes without saying that my mention of the existence of these replicas should not be construed as a recommendation.

[Steve]

Great care must be taken when removing the original HMV rubber isolator. The backs of late No.4 and all No.5a/5b soundboxes are pot metal and easily broken, so much so that UK dealer John Sleep www.windupgram.co.uk has had replica backs manufactured in modern light alloy.

But these are not identical to the originals and in my opinion miss the whole point of the original design entirely with their mistakenly manufactured solid collar backs which do not have any space inside for the rubber isolators at all, meaning there is a full mechanical fix and continuous contact between the tonearm and soundbox. A complete failure to understand the purpose of isolating the motor vibrations from the soundbox and unwanted resonances from colouring the sound waves emitting from the diaphragm.

It goes without saying that my mention of the existence of these replicas should not be construed as a recommendation.

No, I didn't think so!
Of course, those collectors with the appropriate skills and machinery might wish to bore the hole to a wider internal diameter to suit a new Meltrope style isolator.